Convertible rocking chair



April 21, 1942.

M. THUM CONVERTIBLE ROCKING CHAIR Filed Jan. 31, 1940 Patented Apr. 21,1942 UNITED STATES PATENT OFFICE CONVERTIBLE ROCKING CHAIR Martin Thum,Rochester, N. Y.

Application January 31, 19:10, Serial No. 316,645

4 Claims. (Cl. 15573) The present invention relates to rocking chairs,and more particularly to that class of chairs commonly referred to asconvertible rocking chairs in that they are capable of use as a rock ingchair, a reclining chair, or as an ordinary chair, at the option of theuser.

Many chairs of this character are so constructed that the rockerelements do not extend beyond the body, seat or legs of the chair,either at the front or rear of the chair, yet despitejthis fact thechair possesses stable equilibrium at all times whether occupied orunoccupied and whether the chair is used in the ordinary manner, as arocker, or as a reclining chair.

The improved rocking chair comprising the present invention is noexception and likewise is so constructed that it is devoid of forwardlyor rearwardly projecting rockers, yet it possesses the further advantagethat it does not involve the usual common danger to objects positioneddirectly beneath the rocker assembly, to children, domestic animals orthe like.

Furthermore, the rocker assembly is so constructed that the function ofthe chair as a rocking chair is not affected despite the fact that anobstacle such as the edge of a rug may be positioned directly beneaththe chair.

The provision of such a rocking chair being the principal object of theinvention, it is a further object thereof to provide a rockerconstruction or assembly for chairs in which the It is another object ofthe invention to pro vide such a rocker construction which still retainsits convertible features in that it may be used either to permit rockingof the chair or to maintain it in its inclined or upright positions.

Yet another object of the invention is to provide a rocker constructionor assembly which, unlike common rockers having shifting fulcrums, willnot gradually creep forwardly or rearwardly on the supporting surfaceupon continued use of the rocking chair in its rocking capacity. Asimilar and related object of the invention is to provide a rockerconstruction which will prevent the rocking chair to which it is appliedfrom leaping forwardly when the chair is rocked violently, this being aphenomenon common to most rocking chairs having shifting fulcrums.

A still further object of the invention, in a modified form thereof, isto provide a rocking chair construction in which the chair, despite itsrocking features, is supported for voluntary shifting thereof on thesupporting surface by casters, or at least by a semi-caster effect.

It is another object of the invention to provide a rocking chair of thecharacter set forth above which, although it presents no shiftingfulcrum on the supporting surface together with the dangers attendantthereon, at the same time presents the appearance of a rocking chair andis instantly recognizable as such.

It is still another object of the present invention to provide a chairhaving front legs and a rear supporting means in the nature ofoppositely disposed fulcrum means arranged beneath the chair, forwardlyof the back of the chair, at

points beneath the chair whereby the latter is easily moved or rockedfrom a normal position to a tilted position, the said rear fulcrumsupporting means upon which the chair may be rocked or tiltedfunctioning Within a very limited space beneath the chair body incontact with the supporting surface, and with the front legs providing afour-point chair supporting means. The result is that the major portionof the weight of the chair and its occupant is carried by the fulcrumingmeans both in normal or reclined position of the chair and ease ofrocking in either direction is made possible.

The provision of a rocking chair possessing the features indicated abovein which the rocker construction possesses no parts that are movablerelative to each other or to the chair body and which therefore isunlikely to get out of order; one which is rugged and durable; one whichis comparatively inexpensive to manufacture; and one which is welladapted to perform the services required of it, are further desideratathat have been borne in mind in the development and production of thepresent invention.

Other objects and advantages of the invention, not at this timeenumerated, will become apparent as the following description ensues.

In the accompanying single sheet of drawings:

'Figure 1 is a side elevational View of a chair to which one form of theimproved rocker construction comprising the present invention has beenapplied, the full lines illustrating the chair in its normal uprightposition and the broken lines illustrating he same in its rec-liningposition.

Figure 2 is a side elevational view similar to Figure 1 showing amodified form of the rocker construction.

Figure 3 is a fragmentary side elevational view of a chair showing afurther modified form of the rocker construction applied thereto.

Figure 4 is a side elevational view similar to Figures 1 and 2 showingyet another modified form of the rocker construction.

Figure 5 is a fragmentary side elevational view similar to Figure 3showing still another form of rocker construction.

Figure 6 is a sectional view taken substantially along the line ti5 ofFigure 5.

Figure '7 is a fragmentary side elevational view similar to Figures 3and 5 illustrating an additional modified form of rocker construction.

Figure 8 is a sectional view taken substantially along the line 3-8 ofFigure '7.

Figure 9 is a perspective View of a base or support for a chair bodyhaving associated therewith convertible rocker features designedaccording to the principles of the present invention.

Referring now specifically to Figure 1, the improved rocker constructionis shown for illustrative purposes as being applied to an upholsteredchair ID having a seat 12, a back It, and arms 16 forming what may beconsidered the body of the chair Ill. The base of the chair body isprovided with a pair of depending front legs or supports 18 and a pairof depending rear legs or supports 20, the latter if desired beinginclined rearwardly.

Extending rearwardly from points medially of the height of the frontlegs i2 and only slightly elevated from the supporting surface are apair of parallel extending members each being in the form of a rail orbar, and which preferably terminate at points well within the verticalprojection of the chair body and which, when the front legs 18 are incontact with the floor or other supporting surface, extend substantiallyparallel to the latter. The members 22 are preferably of rectilineardesign or substantially so.

The members 22 are secured adjacent their rear ends as at 24 to the rearlegs or supports 2t! and underlie the same and extend beyond the I rearlegs as at 25 a distance sufiicientonly to lend a degree of stableequilibrium to the chair as a whole when the latter is in its recliningposition as shown in broken lines and whether the chair is vacant oroccupied. By thus extending beyond the inclined legs 25! and projectingrearwardly therefrom in spaced relation to the supporting surface themembers 22 give the general appearance of the usual rocker elementsemployed in conventional rocking chair constructions. If the rear legs2i! are sufficiently inclined from the vertical, it is obvious that themembers 22 may terminate at the inside of the legs 2? and the chair willstill maintain a degree of stable equilibrium in its reclining position.

In order that the chair may be rocked from its full line uprightposition to its dotted line reclining position and vice versa, a sharplyrounded protuberance 26 or rocker element is formed on the underneathside of each member 22 medially of the front and rear legs 18 and 2trespec tively, and preferably nearer the latter than the former. Toinsure accurate front and rear rocking movement of the chair and toprevent sidewise cantingof the same, the protuberances 26 are directlyoppositely disposed on each side of the chair and their distance fromthe rear legs, and from the rear ends of the rocker elements 22, is amatter that may be determined by the specific character of the chair towhich the rocker construction is attached and by the extent and natureof the rocking movement desired as will appear presently. The height ofthe protuberances 2'5, 1. e. the distance from the supporting surface tothe lower edge of the rocker elements 22 at the protuberances, ispreferably substantially equal to the distance that the front legs l8project beneath the members 22, thus causing these latter elements toextend substantially parallel to the supporting surface when the chairis in its normal upright position as previously described.

The protuberances 26 are preferably located on the members 22 at pointsslightly rearwardly of the center of gravity of the chair body whenoccupied, or at least at a point very close to the calculated center ofgravity of chair and its cccupant in order that the protuberances willjointly provide a stationary fulcrum for the chair on the supportingsurface at a point sufficiently Well beneath the chair that the occupantmay, with little difficulty, rock the chair to either of its two extremepositions. The chair will thus possess a degree of stable equilibriumand have a four point support both in its normal upright position and inits reclining position and, at any inclination between these twoextremes, the chair will possess a degree of unstable equilibriumdepending upon the weight and center of gravity of the combined chairand occupant. It will further be seen that by varying the distance ofthe protuberances 26 from the rear supporting legs 23, the character ofthe rocking action may be varied, while varying the distance the rearends of the members 22 project rearwardly beyond the protuberances 26,the inclination of the chair when in its reclining position may bevaried.

The location of the protuberances 26 on the members 22 is thuspredetermined not only by the weight and location of the center ofgravity of the chair body, but also by the extent and slope of the chairbottom [2 and by the height and slope of the chair back it, these latterfactors being significant in determirdng the center of gravity of thechair and its occupant. These considerations are preferably adhered toin de signing the rocker construction for any particular chair eventhough the chair when not occupied is incapable of remaining stable inits reclining position.

In connection with the form of the invention just described andillustrated in Figure 1, it is to be noted that the members 22 are notto be confused with the usual runners employed in connection with theordinary rocking chair. Such runners shift their point of contact withthe supporting surface as the chair is rocked thus causing the chair tocreep forwardly ppon continued use. Vifhere the chair is rockedviolently it will, because of the shifting center of gravity of thechair body, leap forwardly, so to speak, sometimes damaging the chairand sometimes harming the occupant. In the present instance the centerof gravity of the chair body is given little freedom to shift. At themost, it will shift from a point slightly forwardly of the protuberances26 to a point slightly rearwardly thereof, thus placing the chair gentlyin either of its extreme positions when rocked from one to the other.

The members 22, being thus spaced from the supporting surface and beingincapable of contacting the latter except at the extreme rear endsthereof when the chair is in its reclining position, there is littleopportunity for articles positioned beneath the members 22 to becomecrushed and the always present danger of injuring children or domesticanimals that exists in connection with other types of rockerconstructions is eliminated. Furthermore, the rocking features of therocker construction are not interfered with despite the presence ofarticles beneath the members 22. Thus the chair may straddle the edge ofa rug or other obstacle and still function as a rocking chair withoutdifficulty. When the chair is used for rocking purposes, no accumulatedpotential rocking energy can be stored in the rocker construction, andconsequently no excessive momentum is encountered tending to upset thestable equilibrium of the chair or its occupant.

In Figure 2 a modified form of rocker construction involvingsubstantially the same principles of operation as the rockerconstruction of Figure l is shown. In this form of the invention, forillustrative purposes, the chair body construction including the seat12, back l4 and arms It remains substantially the same while themodifled rocker construction permits the chair to co cupy a positionfairly close to the supporting surface, thus giving the appearance ofthe ordinary easy or Morris chair. The front legs or supports 28 arerelatively short compared to the legs 18 and are entirely independent ofthe rocker elements 32. These latter elements are secured to theunderneath side of the chair body at the rear corners thereof and areformed with downwardly projecting protuberances 3'? which, like theprotuberances 25, are sharply rounded. The rocker elements 32 are formedwith extensions 35 which project slightly beyond the rear edge of thechair bottom and control the inclination of the chair when the latter isin its reclining position. The extensions 35, however, do not projectrearwardly beyond the vertical projection of the chair upon thesupporting surface for reasons that are well understood in connectionwith. the extensions 25. The height of the protuberances 36 issubstantially equal to the height of the front legs 28 and thus thechair, when in its upright position presents an underneath surface whichis spaced from and substantiall parallel to the supporting surface.

In the form of the invention just described, the same advantageousfeatures outlined in connection with the form of the invention shown inFigure l are attained while at the same time the elimination of rockerelements that are coextensive with the length of the chair causes thelatter to take on the appearance of an easy chair despite the fact thatthe chair is capable of being used as a rocking chair.

In the form of the invention illustrated in Figure 3, the rockerconstruction remains substantially the same as in the form shown inFigure 1 with the exception that the protuberances 26 on the members 42have been omitted and in their stead there has been substituted atraction roller 46 '(see also Figure 6) which is rotatably supportedbetween a pair of ears 4'! formed on the underneath side of the members42. The combined height of the rollers 46 and ears 4! is substantiallyequal to the distance that the front legs 48 project below the members42 and thus, in addition to the advantageous features present inconnection with the other forms of the rocker construction, asemi-caster effect is obtained whereby the chair may manually be shiftedon the supporting surface with comparative ease.

In Figure 5 somewhat the same condition as that shown in Figure 2obtains, but the rocker construction is modified to cause the chair totake on the appearance of a glider which ordinarily is mounted onrunners. In this form of the invention, the members 52 are secureddirectly to the underneath side of the chair and extend from pointsadjacent the front thereof to points beyond the rear lower edge of thechair but well within the confines of the vertical pro jection of thechair on the supporting surface. The front legs 58 project downwardlyfrom the members 52 at the front of the chair a distance equal to thecombined height of the rollers 56 and their supporting ears 5! as in theform of the invention shown in Figure 3. Thus a semicaster effect isattained while the advantages set forth in connection with the otherforms of the invention are preserved.

In Figure 4 the rocker construction is substantially the same as thatshown in Figure 2 except for the substitution of the rollerconstructions 66, 61, for the protuberances 36 on the members 62, Inthis manner, the chair takes on the appearance of an easy or Morrischair while still possessing the same rocking features and thesemi-caster gliding effect.

In Figures 7 and 8, a rocker construction designed for use on a soft oryielding supporting surface, as for example on a thick soft rug or on alawn, is disclosed. The true rocking chair type of construction shown inFigures 1 and 3, rather than the easy chair or glider chair construction of Figures 2 and 5, has been selected for illustrativepurposes only. In this form of the invention, a pair of foot members 16having foot portions 19 and web portions 8! have their latter portionspivoted between ears I! formed on the underneath side of the rockerelements 12. The combined height of the foot members and ears issubstantially equal to the distance the front legs 18 project below therocker elements 72 in order that the rocker elements will extendsubstantially parallel to the supporting surface when the chair is inits upright position. The foot portions 19 of the foot members 76 are ofsufficient extent that they will not sink into the relatively softsupporting surface and thus the chair may be utilized as an outdoorrocking chair despite the condition of the ground.

In the form of the invention shown in Figure 9, the convertible rockingfeatures of the present invention are incorporated in a chair frame orbase which, if desired may be in the form of an integral casting towhich the chair body (not shown) is secured or on which it is mounted inany suitable manner. The frame 90 includes a front rail 92, a pair ofparallel side rails 94, and a curved rear rail which merges gently intothe contour of the side rails 94. A pair of rocker elements 98,including protuberances similar to the protuberances 25 and 36 ofFigures 1 and 2, depend from the side rails 94 and are designed forcontact with the supporting surface at spaced points which are slightlyrearwardly of the center of gravity of the combined chair body andframe. A limit stop Hill is formed centrally of the curved rear rail 96and determines the inclination of the chair body in the reclinedposition thereof. Relatively short legs or supports I02 depend from thefront corners of the frame 90 and are of a height corresponding to theheight of the rocker elements 98 in order that the major portion of theside rails 94 will remain spaced from and parallel to the supportingsurface ,when'the chair is in its'upright position.

The invention is not to be limited to the exact arrangements of .therocker constructions shown in the accompanying drawing or described inthe specification as various changes may be resorted to withoutdeparting from the spirit of the invention. For example, the footconstruction shown in Figures '7' and 8 is capableof use in connectionwith rocker constructions designed along the lines of those shown in anyof the preceding figures. Onlyinsofaras the invention has particularlybeen pointed out in the accompanying claims is thesame to be limited,

What is claimed is:

1. In a convertible chair construction, a chair body having a bottom,front and rearlegs depending from the bottom at-each side thereof, railssecured to each front leg at a point spaced upwardly'from the lower endthereof, said" rails extending rearwardly beneath the chair in parallelism and terminating within the vertical projection of the chair,and a pair of relatively short oppositely positioned protuberancesdepending from said rails at points slightly rearwardly of the center ofgravity of the chair and for-- wardly of the rear ends of the; rails,said protuberances providing a substantially fixed fulcrum for the chairupon its supporting surfacem the height of said protuberances beingsubstantially equal to the distance from the supporting surface to saidupwardly spaced points whereby the rails are normal-lymaintainedparallel to and spaced from the supporting surface, therear legs beingconnected tothe rails at-points located between the rear ends of therails and the protuberances.

2. A rocker construction for chairs and the like comprising a'pairofelongated tiltab-le rail for contact with a supporting surface, and arelatively short depending leg formed on the forward end of each memberand of an extent substantially equal to the extent of thefulcrum memberwhereby the majorportion" of the rail-like memher is normally maintainedslightly elevated from the supporting surface, the extreme rear portionporting the side rails in spaced relationship from the surface formovement of the chair from a forward upright position to a rearwardlyinclined position, a pair of spaced legs depending from the basestructure at the front thereof and designed for contact with thesupporting surface for limiting the forward rocking movement of thechair body and determining its forward upright position, saidprotuberances and legs being substantially of equal extent and servingto maintain the side rails slightly elevated from the supporting surfaceand substantially parallel thereto when the chair is in its forwardupright position, and a limit stop mounted on the rear of the basestructure and designed for contact with the supporting surface forlimiting the rearward rocking movement of the chair body and determiningits rearwardly inclined position.

4. In a convertible rocking chair construction, a chair body having abase structure including a pair of side rails, a relatively shortprotuberance depending from each side rail medially thereof at a regionslightly rearwardly of the center of gravity of the chair, saidprotuberanc-es providing a substantially fixed horizontal fulcrum axisupon which the chair is pivoted for tilting movement, legs dependingfrom the base structure in the forward regions thereof, saidprotuberances and legs serving to support the side rails and maintainthe same spaced above the supporting surface on which the chair ismounted in the normal position of the latter, the portions of said railsrearwardly of the protuberances being adapted for contact with thesupporting surface to limit the rearward tilting movement of the chair.

MARTIN THUM.

